An object of mass m moves to the right with a speed v. It collides head-on with an object of mass 3m moving with speed v/3 in the opposite direction. If the two objects stick together, what is the speed of the combined object, of mass 4m, after the collision

the answer is 0 m/s

Explanation:

This question is describing the law of conservation of momentum

First object has mass =m

velocity of first object = v

second object = 3m

velocity of second object = v/3

the law of conservation of momentum is expressed as

m1V1 - m2V2 = (m1+ m2) V

substituting the parameters given;

making V as the subject of formular

V =

V =

V =

= 0 m/s

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .